1. Field of the Invention
The present invention relates to a media processing device, which accesses an external storage device, reads and reproduces media files stored in the external storage device, and stores media files produced by itself through an encoding process in the external storage device, thus enabling the reproduction and storage of the media files without being provided therein with a storage module for storing the media files.
2. Description of the Related Art
Currently, media processing devices for reproducing and storing media files, such as an MPEG-1 Audio Layer-3 (MP3) player and a voice recorder, have been widely used. FIG. 1 is a diagram schematically showing the construction of a conventional media processing device 100. The conventional media processing device 100 is equipped therein with a non-volatile storage module 140, such as flash memory, and, accordingly, is capable of storing media files received from a host device 180 therein. Additionally, when a command to reproduce a media file is input from a user to the conventional media processing device 100 through a user interface module 120, the conventional media processing device 100 reads a media file from the storage device 140 and transmits the data of the media file to a signal processing module 150 so that the data of the media file are encoded according to a certain signal processing method, such as an MP3 encoding method.
For the purpose of the above-described transmission and reception of the media file, the host device 180 and the media processing device 100 are each provided with a transmission medium access function. FIG. 1 illustrates the case where a Universal Serial Bus (USB) transmission medium is used, as an example. In USB technology, when two devices are connected to each other through a USB transmission medium, one device performing a master function is referred to as a USB host while the other device performing a slave function is referred to as a USB device. In the case where the media processing device 100 receives a media file from the host device 180 as shown in FIG. 1, the host device 180 corresponds to the USB host and the media processing device 100 corresponds to the USB device. For this purpose, the host device 180 includes a USB host module 190 and the media processing device 190 includes a USB device module 130.
An Institute of Electrical and Electronics Engineers (IEEE) 1394 transmission medium and a wireless Local Area Network (LAN) can be used as the transmission medium for that purpose, besides the USB transmission medium. As for the connection between the two devices, the devices may be connected to each other through a cable, may be provided with connection ports for the connection therebetween, or may be wirelessly connected to each other through a wireless medium. In the case where IEEE 1394 technology or wireless LAN is used, a different scheme other than the above-described host-device scheme can be employed. For example, in the case of IEEE 1394 technology, a peer-to-peer scheme other than the master-slave scheme is used, and the host device 180 corresponds to a Serial Bus Protocol 2 (SBP2) initiator and the media processing device 100 corresponds to a SBP2 target according to SBP2 that is a higher-rank management protocol. For example, i-Pod of Apple Computer, Inc. is a typical MP3 player utilizing an IEEE 1394 transmission medium. Meanwhile, in general digital transmission media including a USB transmission medium and an IEEE 1394 transmission media, the host device 180 may be generally modeled on a controller and the media processing device 100 may be generally modeled on a target.
Three issues regarding the conventional media processing device 100 are cost reduction and the miniaturization and weight of a product. The storage device 140 would be a great hindrance to address these issues. Further, with respect to the storage capacity of the storage device 140, there is another problem in which user demand for upgrading storage capacity is raised because storage capacity becomes relatively insufficient when one or two years elapse after the products of the storage device 140 have been marketed. In the meantime, external storage media for supporting high performance digital transmission media, such as a USB transmission medium or an IEEE 1394 transmission medium, are popularized, but are problematic in that they are of questionable utility.